A new 2026 joint statement from the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the Global Lung Function Initiative aims to resolve decades of confusion over how spirometry should be interpreted to diagnose COPD.
For more than 30 years, clinicians have debated which threshold best defines airflow obstruction. GOLD has traditionally recommended a simple fixed ratio (FEV1/FVC <0.7), while GLI has supported the “lower limit of normal” (LLN), which adjusts for age, sex and population differences. Conflicting guidance has led to uncertainty in both primary and specialist care, contributing to underuse of spirometry and widespread underdiagnosis of COPD.
The new statement does not declare one approach universally superior. Instead, it clarifies that the two methods serve different purposes. The LLN is best suited for describing airflow limitation across populations and accounting for normal physiological variation. In contrast, the fixed ratio remains the preferred, pragmatic tool for confirming COPD in symptomatic individuals with relevant exposure histories, such as smoking.
A key message is that spirometry results must always be interpreted in clinical context. Neither GOLD nor GLI supports diagnosing COPD based on spirometry alone without symptoms and risk factors. The statement reinforces that spirometry is a biological measurement—not a standalone diagnosis.
Importantly, the groups emphasise that differences between the two thresholds affect only a small proportion of patients and should not be a barrier to testing. Simplifying interpretation is intended to encourage wider use of spirometry, which remains essential for confirming COPD.
Overall, the joint statement represents a pragmatic consensus: use the fixed ratio to confirm COPD in appropriate patients, recognise the value of LLN for broader assessment, and prioritise clinical judgement. By ending a long-running debate, GOLD and GLI hope to improve diagnostic confidence, increase testing, and reduce the global burden of undiagnosed COPD.
Source:
News-Medical. (2026). New statement released on the use and interpretation of spirometry for COPD diagnosis.
The Limbic. (2026). GOLD and GLI end 30-year spirometry threshold debate.
